1. Field of the Invention
The present invention relates to a dental tooth brush used for cleaning teeth, and, more particularly, to an improvement of a cleaning appliance used to clean spaces between teeth, i.e., interdental spaces, which is called an interdental tooth brush or an ID brush (hereinafter referred to as an interdental tooth brush).
2. Description of the Prior Art
Cleaning of the tooth surfaces with a dental tooth brush has been widely practiced as an effective method of preventing the diseases associated with teeth, such as carious tooth and periodontal disease, hindering the progress of these diseases or healing them. The dental tooth brush enables the surfaces of the tooth surfaces, i.e., labial or buccal surfaces and lingual surfaces, to be cleaned, but fail to clean the spaces between teeth, i.e., the interdental spaces. However, it is the interdental spaces where food lees are most likely to stay that need to be cleaned to prevent diseases. Therefore, attention has been paid in recent years to interdental tooth brushes or dental flosses that specifically clean the interdental spaces.
FIG. 8 shows one example of the interdental tooth brush which is one of the tooth cleaning appliances. A thin wire or plastic rod is provided as an axis at the forward end of a handle which is to be gripped by a hand. Bristles as seen in a plane perpendicular to the axis are planted radially and in the same length in all the directions. The brush has a cylindrical, conical or barrel-like shape when seen along the longitudinal axis thereof.
Since the bristles as seen in a plane perpendicular to the axis of the brush are planted radially and in the same length in all the directions, the known interdental tooth brush is very useful to an intact person whose teeth or gingivas are not defected remarkably or retracted or a person whose tooth condition is close to that of the intact person. However, it is not useful to a person if he or she has teeth or gingivas which have become unsound, i.e., if a person has gingival pockets or free gingivas (hereinafter referred to as gingival pockets) in which spaces are formed between the teeth and roots of the teeth due to periodontal disease or other diseases: it does not reach the inside of the gingival pockets because the bristles have a circular cross-section, making a sufficient degree of cleaning difficult.